/* Copyright (c) 2007 HomeAway, Inc.
 *  All rights reserved.  http://www.atomserver.org
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package org.atomserver.utils.collections;

import java.util.Map;
import java.util.HashMap;

/**
 * @author Chris Berry  (chriswberry at gmail.com)
 * @author Bryon Jacob (bryon at jacob.net)
 */
public class BidirectionalMap<K, V> extends HashMap<K, V> {
    private Map<V, K> reverse;
    
    public BidirectionalMap(Map<K, V> map) {
        this.putAll(map);
        reverse = new HashMap<V, K>(map.size());
        for (K key : map.keySet()) {
            reverse.put(map.get(key), key);
        }
    }
    
    public K reverseGet(V value) {
        return reverse.get(value);
    }
}
